 /*******************************************************************************
  * Copyright (c) 2002, 2006 IBM Corporation and others.
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License v1.0
  * which accompanies this distribution, and is available at
  * http://www.eclipse.org/legal/epl-v10.html
  *
  * Contributors:
  * IBM Corporation - initial API and implementation
  *******************************************************************************/
 package org.eclipse.ui.internal.cheatsheets;

 import java.util.HashMap ;
 import java.util.Map ;

 import org.eclipse.core.runtime.Platform;

 public class CheatSheetStopWatch {
     private static CheatSheetStopWatch stopWatch = null;

     private Map table;

     private CheatSheetStopWatch() {
         
     }
     
     public static CheatSheetStopWatch getInstance() {
         if(stopWatch == null) {
             stopWatch = new CheatSheetStopWatch();
         }
         
         return stopWatch;
     }
     
     public void start(String key) {

         Entry entry = getEntry(key);
         if (entry == null) {
             entry = new Entry();
             putEntry(key, entry);
         } else {
             resetEntry(entry);
         }
         
         entry.start = System.currentTimeMillis();
     }
     
     public void stop(String key) {
         Entry entry = getEntry(key);
         entry.stop = System.currentTimeMillis();
     }
     
     public long totalElapsedTime(String key) {
         Entry entry = getEntry(key);
         return entry.stop - entry.start;
     }
     
     public void lapTime(String key) {
         Entry entry = getEntry(key);
         if(entry.currentLap == -1) {
             entry.previousLap = entry.start;
         } else {
             entry.previousLap = entry.currentLap;
         }
         entry.currentLap = System.currentTimeMillis();
     }

     public long elapsedTime(String key) {
         Entry entry = getEntry(key);
         return entry.currentLap - entry.previousLap;
     }

     /**
      * Contains the data for an entry in the stopwatch.
      */
     private static class Entry {
         protected long start = -1;
         protected long stop = -1;
         protected long currentLap = -1;
         protected long previousLap = -1;
     }
     
     private Entry getEntry(String key) {
         return (Entry) getTable().get(key);
     }

     private void putEntry(String key, Entry entry) {
         getTable().put(key, entry);
     }

     private void resetEntry(Entry entry) {
         entry.start = -1;
         entry.stop = -1;
         entry.currentLap = -1;
         entry.previousLap = -1;
     }

     private Map getTable() {
         if (table == null) {
             table = new HashMap (10);
         }
         return table;
     }


     public static boolean isTracing() {
         if (CheatSheetPlugin.getPlugin().isDebugging()) {
             String traceTimes = Platform.getDebugOption("org.eclipse.ui.cheatsheets/trace/creation/times"); //$NON-NLS-1$
 if (traceTimes != null && traceTimes.equalsIgnoreCase("true")) { //$NON-NLS-1$
 return true;
             }
         }
         return false;
     }
     
     public static void startStopWatch(String key) {
         if(isTracing()) {
             getInstance().start(key);
         }
     }

     public static void printTotalTime(String key, String message) {
         if(isTracing()) {
             getInstance().stop(key);
             System.out.print(message);
             System.out.println(getInstance().totalElapsedTime(key));
         }
     }

     public static void printLapTime(String key, String message) {
         if(isTracing()) {
             getInstance().lapTime(key);
             System.out.print(message);
             System.out.println(getInstance().elapsedTime(key));
         }
     }
 }

